zlib-download

zlib-download is a skill for Claude Code from psylch/media-master. It costs 79 tokens per session (2,193 once invoked), scanned A, original, MIT.

A book-search and download tool for Z-Library and Anna’s Archive, online services that host or index books and papers.

In plain words
What is it for?
Finding books, research papers, and ebooks, then downloading them when the required credentials and services are configured.
Why use it?
It brings searches from these sources into one command-line workflow instead of making you check them separately. It also checks whether required software and account details are ready.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: reads .claude/ paths.

Part of the media-master plugin — 3 skills shipped together

Good fit Finding books, research papers, and ebooks, then downloading them when the required credentials and services are configured.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/psylch/media-master/zlib-download
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add psylch/media-master --skill zlib-download
Clone the repo
git clone --depth 1 https://github.com/psylch/media-master

Made for: Claude Code.

Or install media-master, the plugin that ships this one along with the rest of its 3 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for zlib-download

README.md
[![agentmods](https://agentmods.dev/badge/skills/psylch/media-master/zlib-download/github.svg)](https://agentmods.dev/skills/psylch/media-master/zlib-download)
Your own site
<a href="https://agentmods.dev/skills/psylch/media-master/zlib-download"><img src="https://agentmods.dev/badge/skills/psylch/media-master/zlib-download/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for zlib-download

Your own site · 80×15
<a href="https://agentmods.dev/skills/psylch/media-master/zlib-download"><img src="https://agentmods.dev/badge/skills/psylch/media-master/zlib-download.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,193 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00079 $0.02193
Opus 5 $0.00039 $0.01097
Sonnet 5 $0.00016 $0.00439
Haiku 4.5 $0.00008 $0.00219

Measured 9d ago against content hash dec6299a3218, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

zlib-download scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (scripts/book.py, scripts/setup.sh, scripts/Zlibrary.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/zlib-download/SKILL.md · 248 lines

How it starts

The opening of the file, as written. The whole thing — 248 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Book Tools

Search and download books from multiple sources through a unified CLI.

Language

Match user's language: Respond in the same language the user uses.

Backends

Backend Source Auth Required Best For
zlib Z-Library (EAPI) Email + Password Largest catalog, direct download
annas Anna's Archive API Key (donation) Aggregated sources, multiple mirrors

Preflight

Before any workflow, run preflight to check environment readiness:

python3 ${SKILL_PATH}/scripts/book.py preflight

Returns standardized JSON:

{
  "ready": true,
  "dependencies": { "python3": {"status": "ok"}, "requests": {"status": "ok"} },
  "credentials": { "zlib": {"status": "configured"}, "annas_api_key": {"status": "not_configured"} },
  "services": { "annas_binary": {"status": "ok"} }
}
  • If ready: true — proceed directly to the Workflow section.
  • If ready: false — follow the Check/Fix table below, then run the Setup flow.
Check Fix
requests missing bash ${SKILL_PATH}/scripts/setup.sh install-deps (or manually: pip3 install requests / uv pip install requests)
zlib not configured Guide user to edit ~/.claude/book-tools/.env — set ZLIB_EMAIL and ZLIB_PASSWORD
zlib expired Cached tokens expired and no email/password in .env. Guide user to re-add credentials to ~/.claude/book-tools/.env
annas_api_key not configured Guide user to donate at Anna's Archive for API key, then add ANNAS_SECRET_KEY to ~/.claude/book-tools/.env
annas_binary missing bash ${SKILL_PATH}/scripts/setup.sh install-annas (or manually: download from annas-mcp releases, extract to ~/.local/bin/annas-mcp)

Setup (First-Time Only)

Only run setup when preflight reports ready: false. Guide the user through configuration interactively.

Step 1: Install Dependencies

Read the full file on GitHub · 248 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 248 lines · 79 tokens per session scan A dec6299a3218

Subscribe to this mod's changes

zlib-download is a skill published in the GitHub repository psylch/media-master (5 stars, last pushed 6mo ago), licensed MIT. It adds 79 tokens to every session and 2,193 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.